1. Field of the Invention
The present invention is directed to an x-ray diagnostic device of the type having a radiation emitter with a beam gating arrangement allocated thereto, a multi-line radiation detector for the production of electrical signals dependent upon the intensity of incident radiation, wherein the radiation emitter and the multi-line radiation detector are arranged opposite one another and can be rotated around a common center in a first operating mode and are stationary in a second operating mode.
2. Description of the Prior Art
An x-ray diagnostic device of the above type, implemented as a computed tomography apparatus, is known from U.S. Pat. No. 5,430,783.
Radiation examinations can be performed on an examination subject with such an x-ray diagnostic device and cross-sectional or overview exposures of the examined region of the examination subject can be shown on a display device from the signals of the radiation detector after processing with a signal processing chain.
A dynamic representation of anatomical subjects in the full field and in real time is not possible due to the relatively narrowly gated useful x-ray beam. A dynamic representation in the full field can only ensue off-line after a successful reconstruction of the signals (acquired in the computed tomography scanning) by an image computer in the signal processing chain. It is, however, desirable to make a combination of the dynamic realtime-imaging (radioscopy) with the advantages of the computed tomography (high contrast resolution by means of narrow gating of the useful x-ray beam) available to radiologists and physicians, particularly for interventional procedures in the human body using catheters and surgical instruments.
A dynamic representation of anatomical subjects in the full field and in real time is not attainable even with an x-ray examination apparatus as disclosed in U.S. Pat. No. 4,920,562 which, besides an operating mode corresponding to that described in the aforementioned U.S. Pat. No. 5,430,783, also has a second operating mode, wherein the x-ray examination apparatus operates as a slotted imaging device. Even so, only a narrow slot is gated, corresponding to the slot width employed in computed tomography, but with the exception that the imaging devices do not rotate around the patient. Radioscopic exposures for overview images of the complete subject cannot be attained with the slotted imaging device.
An object of the present invention is to provide an x-ray diagnostic device of the type initially described, but which allows both dynamic real time imaging (radioscopy) and computed tomography exposures having a high contrast resolution to be made available to the user, with these functions being united in a single x-ray diagnostic device.
The above object is achieved in accordance with the principles of the present invention in an x-ray diagnostic device having a radiation emitter with a controllable gating arrangement allocated thereto, which gates an x-ray beam emitted by the radiation emitter, a multi-line radiation detector for producing electrical signals dependent on the intensity of radiation incident thereon, the radiation emitter and the detector being disposed opposite each other and being rotatable together around a common center in a first operating mode, the gating arrangement in the first operating mode being operated to produce a narrow fan beam and, in a second operating mode of the diagnostic device, the controllable gating arrangement being operated to produce an x-ray beam which substantially completely irradiates the multi-line radiation receiver.
By being able to produce both computed tomography exposures and real time radiographic images with the same device, space savings are achieved, as well as cost savings.